Amphibians are frequently characterized as having limited dispersal abilities, strong site fidelity and spatially disjunct breeding habitat. As such, pond-breeding species are often alleged to form metapopulations. Amphibian species worldwide appear to be suffering population level declines caused, at least in part, by the degradation and fragmentation of habitat and the intervening areas between habitat patches. If the simplification of amphibians occupying metapopulations is accurate, then a regionally based conservation strategy, informed by metapopulation theory, is a powerful tool to estimate the isolation and extinction risk of ponds or populations. However, to date no attempt to assess the class-wide generalization of amphibian populations as metapopulations has been made. We reviewed the literature on amphibians as metapopulations (53 journal articles or theses) and amphibian dispersal (166 journal articles or theses for 53 anuran species and 37 salamander species) to evaluate whether the conditions for metapopulation structure had been tested, whether pond isolation was based only on the assumption of limited dispersal, and whether amphibian dispersal was uniformly limited. We found that in the majority of cases (74%) the assumptions of the metapopulation paradigm were not tested. Breeding patch isolation via limited dispersal and/or strong site fidelity was the most frequently implicated or tested metapopulation condition, however we found strong evidence that amphibian dispersal is not as uniformly limited as is often thought. The frequency distribution of maximum movements for anurans and salamanders was well described by an inverse power law. This relationship predicts that distances beneath 11–13 and 8–9 km, respectively, are in a range that they may receive one emigrating individual. Populations isolated by distances approaching this range are perhaps more likely to exhibit metapopulation structure than less isolated populations. Those studies that covered larger areas also tended to report longer maximum movement distances – a pattern with implications for the design of mark-recapture studies. Caution should be exercised in the application of the metapopulation approach to amphibian population conservation. Some amphibian populations are structured as metapopulations – but not all.

Dispersal and the metapopulation paradigm in amphibian ecology and conservation : are all amphibian populations metapopulations?

Terrestrial habitats surrounding wetlands are critical to the management of natural resources. Al- though the protection of water resources from human activities such as agriculture, silviculture, and urban development is obvious, it is also apparent that terrestrial areas surrounding wetlands are core habitats for many semiaquatic species that depend on mesic ecotones to complete their life cycle. For purposes of conser- vation and management, it is important to define core habitats used by local breeding populations surround- ing wetlands. Our objective was to provide an estimate of the biologically relevant size of core habitats sur- rounding wetlands for amphibians and reptiles. We summarize data from the literature on the use of terrestrial habitats by amphibians and reptiles associated with wetlands (19 frog and 13 salamander species representing 1363 individuals; 5 snake and 28 turtle species representing more than 2245 individuals). Core terrestrial habitat ranged from 159 to 290 m for amphibians and from 127 to 289 m for reptiles from the edge of the aquatic site. Data from these studies also indicated the importance of terrestrial habitats for feed- ing, overwintering, and nesting, and, thus, the biological interdependence between aquatic and terrestrial habitats that is essential for the persistence of populations. The minimum and maximum values for core hab- itats, depending on the level of protection needed, can be used to set biologically meaningful buffers for wet- land and riparian habitats. These results indicate that large areas of terrestrial habitat surrounding wetlands are critical for maintaining biodiversity.

/pdf/biological-criteria-for-buffer-zones-around-wetlands-and-1of77ixc63.pdf

Biological Criteria for Buffer Zones around Wetlands and Riparian Habitats for Amphibians and Reptiles

We investigated the response of Gyrinophilus porphyriticus (Plethodontidae), the spring sala- mander, to timber harvest in headwater streams in New Hampshire (U.S.A.). We conducted cover-controlled, whole-stream surveys for G. porphyriticus in 25 first-order streams in drainages encompassing a range of tim- ber-harvest histories. Streams in two different landscape configurations were chosen, isolated, or paired, based on the presence or absence of a confluent first-order stream—a potential source of immigrants. We an- alyzed salamander abundance with respect to logging history, presence of the brook trout ( Salvelinus fontina- lis ), salamander population connectivity, and other measures of physical habitat and aquatic conditions. In stepwise multiple-regression analysis, the best multivariate model of G. porphyriticus abundance included fish presence/absence; effect category, a combined function of years since harvest and substrate embedded- ness by fine sediment; and landscape configuration. These three factors explained 74% of the variation in G. porphyriticus abundance. G. porphyriticus was less abundant in streams where fish were present, likely be- cause of predation by S. fontinalis or asymmetric competition between these species. Abundance also declined with increasing substrate embeddedness and/or decreasing years since harvest, indicating an effect of fine sediment inputs and harvest history on this species. Finally, G. porphyriticus was less abundant in isolated streams than in paired streams. This result suggests that landscape-scale population connectivity may buffer this species from the negative effects of local (i.e., stream-scale) habitat perturbation. We hope this work will encourage others to develop multiscale models of land-use effects on stream biota and thereby ultimately in- crease the range and effectiveness of conservation strategies for these species.

/pdf/local-and-landscape-scale-predictors-of-salamander-abundance-3ckattu8ww.pdf

Local and landscape-scale predictors of salamander abundance in New Hampshire headwater streams

The evolution and origin of primate social organisation has attracted the attention of many researchers, and a solitary pattern, believed to be present in most nocturnal prosimians, has been generally considered as the most primitive system. Nocturnal prosimians are in fact mostly seen alone during their nightly activities and therefore termed 'solitary foragers', but that does not mean that they are not social. Moreover, designating their social organisation as 'solitary', implies that their way of life is uniform in all species. It has, however, emerged over the last decades that all of them exhibit not only some kind of social network but also that those networks differ among species. There is a need to classify these social networks in the same manner as with group-living (gregarious) animals if we wish to link up the different forms of primate social organisation with ecological, morphological or phylogenetic variables. In this review, we establish a basic classification based on spatial relations and sociality in order to describe and cope properly with the social organisation patterns of the different species of nocturnal prosimians and other mammals that do not forage in cohesive groups. In attempting to trace the ancestral pattern of primate social organisation, the Malagasy mouse and dwarf lemurs and the Afro-Asian bushbabies and lorises are of special interest because they are thought to approach the ancestral conditions most closely. These species have generally been believed to exhibit a dispersed harem system as their pattern of social organisation ('dispersed' means that individuals forage solitarily but exhibit a social network). Therefore, the ancestral pattern of primate social organisation was inferred to be a dispersed harem. In fact, new field data on cheirogaleids combined with a review of patterns of social organisation in strepsirhines (lemurs, bushbabies and lorises) revealed that they exhibit either dispersed multi-male systems or dispersed monogamy rather than a dispersed harem system. Therefore, the concept of a dispersed harem system as the ancestral condition of primate social organisation can no longer be supported. In combination with data on social organisation patterns in 'primitive' placentals and marsupials, and in monotremes, it is in fact most probable that promiscuity is the ancestral pattern for mammalian social organisation. Subsequently, a dispersed multi-male system derived from promiscuity should be regarded as the ancestral condition for primates. We further suggest that the gregarious patterns of social organisation in Aotus and Avahi, and the dispersed form in Tarsius evolved from the gregarious patterns of diurnal primates rather than from the dispersed nocturnal type. It is consequently proposed that, in addition to Aotus and Tarsius, Avahi is also secondarily nocturnal.

Origin and evolution of primate social organisation: a reconstruction.

Although movement patterns should reflect important aspects of a species' ecology, a survey of published information on snake movements reveals few general trends among species, populations, or individuals within populations. Snakes are sometimes difficult to study, and some of the problems associated with them (e.g., crypticity of young) will not be overcome easily. However, general patterns might be more evident if: (1) studies were done over reasonably long time periods; (2) methods of data collection, analysis, and presentation were standardized to some extent; and (3) factors that might affect movement patterns (especially resource requirements and distribution) of different individuals became a focus of attention. An animal's use of space reflects to a large extent the spatial availability of its resources (Waser and Wiley, 1979), whether those resources be food, mates, shelter, or other requirements. Numerous constraints will affect movements of individuals. For example, animals that maintain spacing between individuals will be influenced by the presence or absence of conspecifics. Movements of ectothermic animals will be limited temporally and spatially to some degree by the thermal regime of the environment (e.g., Peterson, 1982). Predators and interspecific competitors similarly might constrain activity patterns of a species. Effects should differ among populations of a species in different environments, and among subgroups (e.g., sexes, ages) within populations if those subgroups differ in their requirements. Clearly, the determination of movement patterns and the factors that influence such patterns is integral to both theoretical and applied ecology. Although the aim of theory is to delineate general patterns in nature, such delineation ultimately depends upon information from a wide range of taxa. Movements of snakes frequently have been studied, but these animals are scarcely mentioned in the most recent collection of articles on animal movements, and then in 1 Author to whom correspondence should be addressed. 2 Present address: Department of Zoology, University of Alberta, Edmonton, Alberta, Canada T6G 2E1. only one paper (viz., Mace et al., 1984). The only serious attempt to review published information and draw broad conclusions about snake movement patterns has been that of Gregory et al. (1987). Gregory et al. summarized, in a general way, the methods used to study movements of snakes, methods used to calculate home ranges, and strengths and weaknesses of the various methods; they also attempted to elucidate general trends from the data available. However, a detailed summary of the data set was not included in that review. We present such a tabulation here in the hope that it will provide the beginning of a comparative data base, point out the variability of the kinds of information available for a wide spectrum of populations, and indicate where major gaps exist.

A Tabular Survey of Data on Movements and Home Ranges of Snakes

Radioisotope tagging and tracing techniques revealed the average home range size of five Desmognathus fuscus with 40 or more points of detection and observed over a period of 32-59 days, to be 48.4 m2 (range, 25.2 m2-114.5 m2). Of 14 salamanders studied, the maximum movement in a 24 hr period was 17.1 m (in 10 hr 25 min). Most recorded movements were of distances less than 2 m. Most movements began between 0600 and 0900 and between 2100 and 2400. The salamanders had peaks of activity at 0800 and 2300. The lowest activity was seen at 0300 and at 1600, average temperatures being 17.0?C and 29.0?C respectively. During and after rainfall the animals were often found out of the stream channel. In daylight wet periods the peaks of movement were exaggerated whereas in nighttime wet periods the movements were similar to nighttime dry periods. The two most active animals were a male and a female, the most quiescent were gravid females.

https://www.jstor.org/stable/info/1442077

Home Range, Movements, and Activity of the Dusky Salamander, Desmognathus fuscus

Movements of 10 eastern worm snakes (Carphophis amoenus amoenus) were studied using radioisotope tagging and tracing techniques. The study was conducted at Robinson Forest, Breathitt County, Kentucky, from early May to late October 1966. Snakes were tagged subcutaneously, using a hypodermic needle and plunger apparatus, with 50—80 μc Cp60 alloy wire tags. Detection apparatus consisted of a Victoreen model 489 Thyac II survey meter equipped with earphones, shoulder strap, and scintillation probe mounted at one end of a 3—m tubular aluminum pole. Each snake was located 46 to 89 times. Home ranges were calculated using the minimum area method and averaged 253 m2 (range, 23—486 m2). The longest known movement during a 24 hr period was 45 m (in 14 hr 30 min). Most movements were initiated in late afternoon and early evening. Most periods of activity were of less than 12 hr duration. Periods of inactivity ranged from a few minutes to over 14 days. Snakes displaced distances of 150, 400, and 800 m from where captured exhibited no homing ability.

Home Range, Movements, and Activity of the Eastern Worm Snake, Carphophis Amoenus Amoenus

Radioisotope tagging and tracing techniques were used to study home range, movements and diel activity of Scalopus aquaticus. Home range areas of seven moles were calculated after each had been located periodically during periods ranging from 11 months to 3 years. The mean home range area was 0.74 ha; males averaged 1.09 ha, and females 0.28 ha. Diel activity was recorded for 100 complete 24-hr periods. Moles were active at all hours of the day and night, but there were two primary periods of activity, one from 0800 to 1600 hr and one from 2300 to 0400 hr. Periods spent in the nest ranged from a few min- utes to 6 hr 25 min and averaged 3 hr 9 min. Periods out of the nest averaged 5 hr 26 min. Each mole used a single nest for inactive periods during cold weather; during warmer weather no specific location was used.

http://www.jstor.org/stable/pdfplus/2424406.pdf

Michael J. Harvey

Papers

Home Range, Movements, and Activity of the Dusky Salamander, Desmognathus fuscus

Home Range, Movements, and Activity of the Eastern Worm Snake, Carphophis Amoenus Amoenus

Home Range, Movements, and Diel Activity of the Eastern Mole, Scalopus aquaticus

Notes on Plecotus Townsendii Virginianus in Kentucky

Effect of radioactive tags on the activity of rodents.